SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57e1fadebf314aa246c0c9d2236d3fbcc652e7e473fa827a9823a1a7df3807fe' 
  AND token = 'EqJpzYZdj+cYryaFnPJDeXvcbxJ39mB8VPYRDQtsAwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}